Alves moved to the Premier League team from Heerenveen in January for about 16 million euros but AZ claim they already had an agreement to sign the 27-year-old.
"I always speak with new players," Van Gaal told the commission. "In the conversation, which lasted about 20 minutes, I pointed out to Alves that he should join our training on January 7 and that he should not come too late. He promised me that."
Copyright (c) PA Sport 2008, All Rights Reserved.